System and method for limiting welding output and ancillary features

ABSTRACT

A system and method for limiting welding output and ancillary features is provided. In one embodiment, a portable generator system includes a power generator configured to generate electrical power appropriate for welding or plasma cutting. The generator system also includes power conversion circuitry coupled to the power generator and configured to receive power from the power generator and to provide output power. The generator system includes at least operator accessible input for receiving an operator input parameter. The generator system also includes an output power limiting device not adjustable by the operator and configured to selectively limit output power from the power conversion circuitry.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/105,580, entitled “SYSTEM AND METHOD FOR LIMITING WELDING OUTPUT ANDANCILLARY FEATURES,” filed May 11, 2011, which claims priority to andbenefit of U.S. Provisional Patent Application No. 61/355,985, entitled“GENERATOR/WELDER OUTPUT SELECTOR,” filed Jun. 17, 2010, each of whichis herein incorporated by reference in its entirety.

BACKGROUND

The invention relates generally to generator systems and, moreparticularly, to a system and method for limiting welding output andancillary features.

Portable engine-driven generators are commonly used to provideelectrical power in locations where conventional electrical power is notreadily available. Both gasoline and diesel engines are used to drivesuch generators, and the power produced is typically 120 VAC and/or 240VAC. One specific generator application is for welding processes andthese units are commonly known as portable engine-driven welders. Theseunits include a control system to regulate the power produced by thegenerator, thereby making it suitable for an arc welding operation.Typical welding operations for which these units are often intendedinclude stick electrode welding, metal inert gas (MIG) welding, tungsteninert gas (TIG) welding, or plasma torch cutting, although in some caseslimited process selection is provided.

Increasingly, a rental market has developed for portable engine-drivenwelders. Renting establishments may, for example, provide the portableengine-driven welder attached to a trailer for easily transporting thewelder, or smaller welders may be placed in a work vehicle. The rentingestablishment may desire to provide the portable engine-driven welder tocustomers having a variety of needs. For example, customers may desireonly certain features incorporated into the portable engine-drivenwelder. When possible, an appropriate machine may be selected thataccords with the needs of the renter, with rental rates being chargedaccordingly. However, in many cases, available equipment may simply belarger, of greater power capacity, or more feature-rich than the renterneeds. There is, at present, little flexibility in the ability of therenting establishment to tailor the equipment to the particular needs ofindividual renters, with rental rates being adjusted accordingly. Assuch, there is a need in the field for devices or methods that mightallow for more flexible adaptation of features of portable engine-drivenwelders that might address such situations.

BRIEF DESCRIPTION

In an exemplary embodiment, a portable generator system includes a powergenerator configured to generate electrical power appropriate forwelding or plasma cutting. The generator system also includes powerconversion circuitry coupled to the power generator and configured toreceive power from the power generator and to provide output power. Thegenerator system includes at least one operator accessible input forreceiving an operator input parameter. The generator system alsoincludes an output power limiting device not adjustable by the operatorand configured to selectively limit output power from the powerconversion circuitry. Output may be limited to particular welding powerlevels, voltage levels, current levels, time period, but also to makeavailable or not available auxiliary power, power for lighting and/orhand tools, and so forth. Output may also be limited by particularprocesses, such as welding processes that are available or not availableto the operator.

In another embodiment, a portable engine-driven generator systemincludes an internal combustion engine and a power generator coupled tothe internal combustion engine and configured to be driven by theinternal combustion engine. The generator system also includes a meansadjustable by an operator for controlling output power of the powergenerator. The generator system includes means not adjustable by theoperator for selectively limiting output power from the power generatorfor use in the welding operation.

In another embodiment, a welding power supply limiting method includesreceiving a rental request from a customer for a portable engine-drivengenerator system and determining portions of the portable engine-drivengenerator system to limit using parameters from the customer. The methodalso includes configuring the portable engine-driven generator system tolimit the determined portions of the portable engine-driven generatorsystem using an interface not accessible to the customer.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a perspective view of a portable engine-driven generatorsystem which may employ an embodiment of an output power limitingdevice;

FIG. 2 is a schematic diagram of an embodiment of a portableengine-driven generator system employing an output power limitingdevice;

FIG. 3 is a schematic diagram of another embodiment of a portableengine-driven generator system employing an output power limitingdevice;

FIG. 4 is a block diagram of the control circuitry of FIG. 2 employingan embodiment of an output power limiting device; and

FIG. 5 is a flow chart of an embodiment of a business method for rentingout a portable engine-driven generator system.

DETAILED DESCRIPTION

Turning now to the drawings, FIG. 1 illustrates a portable engine-drivengenerator system 10 which may employ an embodiment of an output powerlimiting device. The portable engine-driven generator system 10 includesan engine-driven generator 12 mounted to a trailer 14. The engine-drivengenerator 12 includes an electrical power generator that is coupled toand driven by an engine. The engine and generator are fully enclosed byan enclosure 15 which includes a top panel 16, side panels 18, and afront panel 20. The enclosure 15 protects the engine and generator fromdust, debris, and rough handling. It should be noted that various sizedand configurations of welding systems may be utilized, and in practice,when used by a renting establishment, multiple systems may be offered,including trailer-mounted systems, skid-mounted systems, portablesystems, and so forth.

A fuel cap 22 is located on the top panel 16 and provides access to afuel tank located within the enclosure 15. The fuel cap 22 may beremoved and fuel may be added to the fuel tank for supplying necessaryfuel to run the engine. An exhaust pipe 24 extends out of the top panel16. Exhaust from the engine is directed by the exhaust pipe 24 out ofthe engine-driven generator 12. The top panel 16 also includes a liftingring 26 which may be used to move the engine-driven generator 12, suchas with an overhead crane.

A control circuitry within the enclosure 15 controls the operation ofthe engine-driven generator 12 and allows the generator 12 to be usedfor welding operations. As such, the front panel 20 includes variouscontrols (e.g., knobs 28 and 30, dial 32, etc.) and connection terminals(e.g., generator power receptacles 34, work cable terminal 36, MIGwelding terminal 38, and TIG welding terminal 40) that allow an operatorto interact with the control circuitry. Specifically, the knob 28 may bean engine control switch for starting and stopping the engine and forselecting the engine speed. Furthermore, the knob 30 may be a voltage oramperage control used to adjust output voltage or amperage depending onthe welding mode. The dial 32 may be a process or contactor switch whichis used to switch between welding modes. For example, an operator mayuse dial 32 to switch between stick electrode welding, MIG welding, andTIG welding.

The generator power receptacles 34 provide various receptacles for usingpower output from the generator. For example, the generator powerreceptacles may include 120 VAC and 240 VAC receptacles. A work cablemay be connected to terminal 36 on the left side of the front panel 20,while a welding cable for MIG welding may be connected to terminal 38 onthe right side of the front panel 20. For TIG welding, a welding cablemay be connected to terminal 40. In certain embodiments, the weldingcable may be connected to terminal 36, while the work cable may beconnected to either terminal 38 or 40.

A limiting or lockout input 42 is also located on the front panel 20.However, in certain embodiments, the input 42 may be positioned anywhereon the enclosure 15. The limiting or lockout input 42 may utilize one ofmany devices which can be used to limit the functionality of theengine-driven generator 12. For example, the input 42 may utilize akeyed selector switch, a connector, a keypad, or a receiver. Inembodiments where the limiting input 42 uses a keyed selector, a key maybe inserted by a vendor into a keyhole and rotated to select thefunctionality or limitations of the engine-driven generator 12. Forembodiments where the limiting input 42 uses a connector, a vendor mayconnect a separate device or cable to the connector to provideinformation to the engine-driven generator 12 to limit itsfunctionality. Specifically, in some embodiments, an enabling device(e.g., dongle) may be attached to the connector to enable functionalityprogrammed into the enabling device. In other embodiments, a cable mayconnect from a computer or other programming device to the connector inorder to send instructions to the engine-driven generator 12 controlcircuitry. When a keypad is used for the limiting input 42, a vendor mayenter a code to access the device 42, and then input codes to limit orenable functionality. For embodiments where the limiting input 42 uses areceiver, the receiver may receive wireless communication from acomputer or other programming device to limit or enable functionality ofthe engine-driven generator 12.

As may be appreciated, various functions of the engine-driven generator12 may be limited or inhibited by the limiting input 42. For example,any welding setting (e.g., type of welding, current level, voltagelevel, etc.), auxiliary power output, lighting system, hydraulic system,air compression system, engine speed, time of use, or generator outputpower, may be limited or inhibited by the limiting input 42. For weldingoperations, the output power as well as particular processes may beselected to be available or not available to the user, such as to limitthe output to one or more of stick welding processes, tungsten inert gas(TIG) welding processes, metal inert gas (MIG) welding processes, pulsedprocesses, constant voltage or constant current processes, cuttingprocesses, and so forth. When the generator 12 receives parameters fromthe limiting input 42, various devices in the generator 12 may limit thefunctionality of the generator 12. For example, control circuitry,switches, or other devices not accessible to an operator may selectivelylimit functionality of the generator 12. It should also be noted thatthe limiting input 42 is intended to be accessible only to vendors, notto operators that may rent the generator 12. The engine-driven generator12 is mounted to the trailer 14 to enable the engine-driven generator 12to be transported. The trailer 14 includes a frame 50 to providestructural support for the engine-driven generator 12. A hitch 52 isattached to the frame 50 to allow the trailer 14 to be connected to atow vehicle for transporting the portable engine-driven generator system10. Wheels 54 are also attached to the frame 50 and support the weightof the frame and the engine-driven generator 12.

FIG. 2 is a schematic diagram of an embodiment of a portableengine-driven generator system 70 employing an output power limitingdevice. The system 70 includes an engine 72 coupled to a generator 74via a shaft 76. The engine 72 may be any suitable internal combustionengine (e.g., gasoline engine, diesel engine, etc.) for driving thegenerator 74. For example, in certain embodiments, the engine 72 may bethree-cylinder diesel engine, such as a 21.7 HP engine operating at anidle speed of approximately 1500 RPM and a welding speed ofapproximately 1850 RPM. Such an engine 72 may be manufactured byCaterpillar of Peoria, Ill. In another embodiment, the engine 72 may bea four-cylinder diesel engine, such as a 24.4 HP engine operating at anidle speed of approximately 1500 RPM and a welding speed ofapproximately 1850 RPM. Such an engine 72 may be manufactured byMitsubishi Engine North America, Inc. of Addison, Ill. Although theengine 72 is depicted, certain embodiments may not include the engine72. Furthermore, the system 70 may provide power appropriate for weldingand/or plasma cutting operations.

The engine 72 rotates the shaft 76 to drive the generator 74 whichprovides power output. The available output power from the generator 74varies based on the generator 74 and engine 72 in the system 70. Forexample, in certain embodiments, the generator 74 may have a rated peakpower output of 12,000 watts and a rated continuous power output of10,000 watts. However, as with engine 72, other generators and powerratings can be employed. A governor 78 is attached to the engine 72 tocontrol the speed of the engine.

The generator 74 provides power for welding and other powered equipmentthat may be coupled to the system 70. Specifically, the generator 74provides power to a power conversion circuitry 80 that may includecircuit elements such as transformers, rectifiers, switches, and soforth. Such circuits are generally known in the art. In someembodiments, the power conversion circuitry 80 may be configured toconvert the generator 74 output power to a weld power 82, an auxiliarypower 84, and power for a light system 86. However, in otherembodiments, the power conversion circuitry 80 may only be adapted toconvert generator 74 output power to a weld power 82.

The weld power 82 includes welding power that may be used for any typeof welding operation (e.g., stick, MIG, TIG, etc.). As such, the weldpower 82 may provide current output of approximately 20 to 410 amps andvoltage output of approximately 14 to 40 VDC for welding. The auxiliarypower 84 may be used to power electrical equipment separate from thesystem 70. Therefore, in certain embodiments the generator 74 mayprovide 120 VAC and/or 240 VAC at approximately 60 Hz. The light systempower 86 may provide power to a lighting system used in conjunction witha welding operation.

In certain embodiments, the system 70 may include a hydraulic system 88and/or an air compressor 90. The hydraulic system 88 is coupled tovalving 92 to enable hydraulic fluid to flow to and from other devices94 to apply a usable force. For example, the hydraulic system 88 may beused for a hydraulic lift, hydraulic actuator, hydraulic motor, etc. Aclutch 96 is coupled to the hydraulic system 88 and may be engaged ordisengaged to control the operation of the hydraulic system 88. The aircompressor 90 is coupled to valving 98 to enable air to flow to and fromdevices 100 that use the compressed air. For example, the air compressor90 may be used for powering tools, providing compressed air to clean asurface, or to increase the air pressure in a device, such as a wheel. Aclutch 102 is coupled to the air compressor 90 and may be engaged ordisengaged to control the operation of the air compressor 90. Eachclutch 96 and 102 may be any suitable clutch, such as a wrap springclutch, belt clutch, or electric clutch. Furthermore, the clutches 96and 102 may be coupled to the shaft 76, such as via a belt or chain, todrive the hydraulic system 88 and the air compressor 90 when the engine72 rotates. As such, when clutch 96 is engaged, the engine 72 drives thehydraulic system 88 and when clutch 102 is engaged, the engine 72 drivesthe air compressor 90.

The system 70 includes control circuitry 104 which may be configured toreceive and process a plurality of inputs, such as limiting or lockoutinputs 106. The control circuitry 104 may use the inputs 106 todetermine instructions to send to the governor 78, power conversioncircuitry 80, and clutches 96 and 102 to limit and/or inhibit the outputor operation of such devices. In addition, the control circuitry 104 mayinclude volatile or non-volatile memory, such as ROM, RAM, magneticstorage memory, optical storage memory, or a combination thereof.Therefore, a variety of control parameters may be stored in the memoryalong with code configured to provide a specific output during operation(e.g., inhibit or limit use of weld power 82, inhibit or limit use ofauxiliary power 84, inhibit use of hydraulic system 88, inhibit use ofair compressor 90, etc.).

The limiting or lockout input 106 receives instructions 108 which maylimit or inhibit the use of any power output, process or processes,system, component, or other feature of the system 70. Furthermore, thelimiting or lockout input 106 may be a keyhole, a connector, or a keypadas previously described in relation to FIG. 1. As illustrated, thesystem 70 may include a transceiver 110 which may receive limitinginstructions wirelessly from a controlling transceiver 112. Thecontrolling transceiver 112 may be operated by a vendor to configure thesystem 70 for use by an operator renting the system 70. For example, theoperator renting the system 70 may desire and pay for limitedfunctionality, therefore the vendor may limit the functionality of thesystem 70 to what the operator paid for. As may be appreciated, anoperator may desire increased functionality after renting the system 70.In such a condition, the operator may be at a remote location relativeto the rental location. Therefore, the transceiver 110 and thecontrolling transceiver 112 may be configured to communicate via acellular or internet connection to enable the vendor to configure thesystem 70 remotely using the controlling transceiver 112.

Specifically, in one presently contemplated scenario, an operator mayenter a store to rent the system 70. A store vendor may provide theoperator with a total cost to rent the system 70. However, under certainconditions, the operator may only desire some functionality of thesystem 70 for a reduced cost, therefore, the operator may be given aprice list to use various functions or operating times of the system 70.The various functions provided to the operator may include: weldingpower for stick welding, welding power for MIG welding, welding powerfor TIG welding, welding current limited to 200 amps, welding currentlimited to 100 amps, auxiliary power, auxiliary power limited to 5000watts, auxiliary power limited to 2500 watts, lighting system power,hydraulic system, and air compressor, for example. As may beappreciated, the various functions provided to the operator are notlimited to the examples provided, but the examples merely representpossible configurations. In addition, an operator may be charged basedon an operating time of various functions or of the complete system 70.Therefore, the system 70 may include limits on the amount of timevarious portions of the system 70 may be used. As such, a customer maypurchase amounts of time they wish to use the system 70 or portions ofthe system 70. Like other purchases described, the system 70 may beprogrammed to be time limited using a wireless, wired, or other option.

The operator may select specific options of the system 70 to be enabled.For example, the operator may select to only enable weld power 82 forstick welding and to enable the hydraulic system 88. After the operatormakes a selection of their desired features, the operator pays for thosefeatures and the vendor configures the system 70 to enable the selectedfeatures using a vendor accessible input. For example, the vendor maysend wireless signals using the controlling transceiver 112 withinstructions to enable or inhibit system 70 features. In someembodiments, the vendor may insert a key into the limiting input 106 toselect desired features. Likewise, a keypad or cable connection may beused to send instructions to the control circuitry 104. The controlcircuitry 104 receives the limiting, inhibiting, and/or enablinginstructions and configures the system 70 using those instructions.

For example, the control circuitry 104 may disable the hydraulic system88 or the air compressor 90 by sending a control signal to either theclutch 96 or the clutch 102 that causes the clutch to remain disengaged.As another example, the control circuitry 104 may disable or limit theweld power 82, the auxiliary power 84, or the light system 86 by sendinga control signal to the power conversion circuitry 80 instructing thepower conversion circuitry 80 to disable or limit the power.Furthermore, the control circuitry 104 may send signals to the governor78 to limit the engine speed 72. It should be noted that the limitingdevice or devices in the system 70 are not accessible to the operator(e.g., they are internal to the system 70 and/or protected by securitycodes, secure communication, or locks).

FIG. 3 is a schematic diagram of another embodiment of a portableengine-driven generator system 120 employing an output power limitingdevice. As illustrated by FIG. 3, switches 122, 124, 126, 128, and 130may be used to inhibit use of portions of the system 120. The switches122, 124, 126, 128, and 130 are controlled by the control circuitry 104.As such, the switches 122, 124, 126, 128, and 130 may be relay, solidstate, or another type of switch. In certain embodiments, the switches122, 124, 126, 128, and 130 may be manual switches that may be actuatedby a vendor. In such an embodiment, the switches may be within a lockedcompartment of the system 120, or the switches may be selected using oneor more keys or other devices which an operator is inhibited fromaccessing.

When a vendor inhibits an operator from using certain functionality ofthe system 120, the vendor sends instructions to the limiting or lockoutinput 106. The control circuitry 104 receives the instructions from theinput 106 and limits or inhibits the functionality of the system 120based on the limiting instructions. Furthermore, enabling instructionsmay be sent from the input 106 to the control circuitry 104. Forexample, the control circuitry may cause any of the switches 122, 124,126, 128, and 130 to be in an open or closed position in order to enableor disable portions of the system 120. More specifically, the controlcircuitry 104 may transition switch 122 to a closed position to enableweld power 82 to flow from the power conversion circuitry 80. Similarly,the control circuitry 104 may configure switches 124 and 126 to enableor disable use of auxiliary power 84 and the light system 86,respectively. Furthermore, the control circuitry 104 may transitionswitch 128 to a closed position to enable the clutch 96 to operate,therefore enabling use of the hydraulic system 88. Similarly, thecontrol circuitry 104 may configure switch 130 to enable or disable useof the air compressor 90. Therefore, system 120 may enable or disablethe use of its devices.

FIG. 4 is a block diagram 140 of the control circuitry 104 of FIG. 2employing an embodiment of an output power limiting device. Processingcircuitry 142 of the control circuitry 104 may receive limitinginstructions from the limiting or lockout input 106 and/or thetransceiver 110. The processing circuitry 142 may use the instructionsto limit the functionality of the engine-driven generator system 120.Furthermore, the processing circuitry 142 may include one or moremicroprocessors, such as one or more “general-purpose” microprocessors,one or more special-purpose microprocessors and/or ASICS, or somecombination thereof. For example, the processing circuitry 142 mayinclude one or more reduced instruction set (RISC) processors.

The control circuitry 104 also includes a memory device 144 and astorage device 146. The memory device 144 may include a volatile memory,such as random access memory (RAM), and/or a nonvolatile memory, such asread-only memory (ROM). In addition, the memory device 144 may store avariety of information and may be used for various purposes. Forexample, the memory device 144 may store processor-executableinstructions (e.g., firmware or software) for the processing circuitry142 to execute, such as instructions for limiting or inhibiting thefunctionality of the welding power, the auxiliary power, the lightingsystem power, the hydraulics system, the air compressor, etc. Thestorage device 146 (e.g., nonvolatile storage) may include ROM, flashmemory, a hard drive, or any other suitable optical, magnetic, orsolid-state storage medium, or a combination thereof. In addition, thestorage device 146 may store data (e.g., security codes), instructions(e.g., software or firmware to limit functionality of the system 120),and any other suitable data.

The processing circuitry 142 is configured to communicate with governorcontrol circuitry 148 to control the operation of the governor 78. Forexample, the processing circuitry 142 may instruct the governor controlcircuitry 148 to adjust the limit of the engine 72 speed used by thegovernor 78. Furthermore, the processing circuitry 142 is configured tocommunicate with power control circuitry 150 to control the operation ofthe power conversion circuitry 80. For example, the processing circuitry142 may instruct the power control circuitry 150 to inhibit the use ofauxiliary power 84 produced by the power conversion circuitry 80.

Likewise, the processing circuitry 142 is configured to communicate withrelay control circuitry 152 which controls the operation of relays 154.For example, the processing circuitry 142 may instruct the relay controlcircuitry 152 to control the relays 154 to open the switch providingauxiliary power 84. In addition, the processing circuitry 142 isconfigured to communicate with clutch control circuitry 156 whichcontrols the operation of clutches 158. For example, the processingcircuitry 142 may instruct the clutch control circuitry 156 to inhibitthe use of the air compressor 90 by disengaging the clutch 102. As maybe appreciated, the control circuitry 104 is configured to receivelimiting inputs, process the inputs, and control power outputs based onthe limiting inputs. Therefore, the control circuitry 104 functions as aoutput power limiting device within the engine-driven generator system70.

FIG. 5 is a flow chart of an embodiment of a business method 160 forrenting out a portable engine-driven generator system. At step 162, avendor may receive a rental request from a customer for a portableengine-driven generator system. Next, at step 164, the vendor andcustomer determine which portions of the generator system to enable,limit, or inhibit. As previously described, the vendor may enable orinhibit all portions of the generator system, or individual portions(e.g., weld power, auxiliary power, lighting system power, aircompressor, and hydraulic system).

At step 166, the vendor configures the generator system with theenabling, limiting, or inhibiting instructions using an interface notaccessible to the customer. For example, the vendor may use securewireless communications, a security key, a proprietary programmingdevice or cable, a proprietary software, or other hardware or softwareto configure the generator system with limiting instructions.Furthermore, in certain embodiments, the generator system may include aninternal log that contains a history of what devices and systems acustomer has used. Such an internal log may be viewed by the vendor incases where a vendor suspects a customer has tampered with the generatorlimiting devices. With such a system, as described, vendors may rent thegenerator system to customers at a variable cost based on the customerneeds. As may be appreciated, fewer or more steps may be included incertain embodiments. In addition, other embodiments may perform themethod 160 in a different order than described.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

1. A welding power supply limiting method comprising: receiving a rentalrequest from a customer for a portable engine-driven generator system;determining portions of the portable engine-driven generator system tolimit using parameters from the customer; and configuring the portableengine-driven generator system to limit the determined portions of theportable engine-driven generator system using an interface notaccessible to the customer.
 2. The method of claim 1, wherein theportions of the portable engine-driven generator system include at leastone of welding power, auxiliary power, light system, hydraulic system,and air compressor.
 3. The method of claim 1, wherein the interfacecomprises a key.
 4. The method of claim 1, wherein the interfacecomprises wireless communication.